Welding unit converter
The conversions that come up when a drawing, a WPS or a machine plate arrives in the units you do not work in.
The ones that catch people
cfh and l/min. Cubic feet per hour is the American unit for gas flow. Twenty cfh looks like a large number next to "10", but it is about 9.4 l/min — a perfectly normal setting. Read it as litres and you will run the arc unshielded.
ipm and m/min. Inches per minute for wire feed. 300 ipm is 7.6 m/min. Here the American number is the big one, and setting 300 on a metric machine is not possible, which at least fails safely.
kJ/in and kJ/mm. Heat input in AWS documents is per inch. A limit of 50 kJ/in is about 2 kJ/mm — a factor of 25 apart, and the same word for both.
Which system a document uses
If it cites EN ISO or ISO standards, it is metric. If it cites AWS, ASME or API, expect imperial units even when the drawing dimensions are metric — mixed documents are common on international projects, and the units are worth checking line by line rather than assuming.
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